Panels that have a layer of foam between an outer skin and an inner substrate are known. Such panels typically have the layer of foam extending across at least part of the substrate layer with the skin extending across the foam layer such that a three layered panel is provided. For example, instrument panels for motor vehicles can include such a panel with the substrate typically made from a polymeric material and the skin made from a flexible sheet material such as leather, flexible polymeric materials and the like. In between the substrate and the skin, the foam layer provides a cushioned appearance and/or feel, which can provide the look and feel of a luxury vehicle and the like. To increase the luxurious look, decorative stitching may be added to the skin of the panel, making it appear to have a higher level of craftsmanship and detail.
Production methods known to those skilled in the art of a panel typically include placing the substrate and the skin in a clamshell foam-filling apparatus such that upon closure of the clamshell apparatus the edges of the skin are joined against appropriate regions of the substrate to create a bounded region between the skin layer and the substrate layer. The bounded region between the skin and substrate is then filled with injectable foam padding. However, a problem arises when the skin is pre-sewn with decorative thread stitching, being that the injectable foam can leak out of the bounded area through a space between the decorative thread and a hole created in the skin by a sewing needle when the decorative thread was stitched in place.